Hyper V - NIC disconnecting at start of backup
We have been noticing an issue with one of our Hyper V servers. It is a Server Core 2012 R2 physical server running a Windows Small Business SErver 2011 (WIn 2008 R2) and a further Win 2008 R2 server. We are running the most recient version ofr ABA 11.7 for Hyper V.
We had been noticing network disconnections overnight every night, initially the reason we noticed it was we have an application on a separate server which connects to a shared folder on the Small Business Server and that crashed every night. Plus a few other issues.
Having worked through the logs we noticed that on the servers there were three logs each night on each of the virtual machines: Miniport NIC 'Microsoft Hyper-V Network Adapter' connected. These logs usually came about somewhere between 20 seconds after the backup start time to about 1minute 20 seconds. There was no log for disconnection of the NIC.
If we change the backup times then the log entry time changes and follows the backup time so its definitely linked to the Acronis backup.
The only similar entires on the physical host are the following logs:
- The Volume Shadow Copy service entered the running state.
- The Microsoft Software Shadow Copy Provider service entered the running state.
- The Acronis VSS Provider service entered the running state.
- Volume ?? (\Device\HarddiskVolumeShadowCopy9) is healthy. No action is needed.
We have changed the VSS settings for the backup to Aconis Provider and System Provider, but this has not changed things.
There is plenty of space on the host drive. Each guest uses a seprate virtual switch/nic and and the management has its own nic.
Any assistance would be great as this has been going on for months now.
The most common reason for VM disconnection during backup is that the VM is backed up in saved state instead of using VSS volume snapshot. This is caused by lack of "Backup (volume checkpoint)" checkbox in Integration Tools settings in Hyper-V VM properties - see details in Acronis KB here. For further troubleshooting it makes sense to enable native Windows Server Backup feature on the Hyper-V host and try backing up the VM (the process will utilize the same core components and workflows as Acronis Backup) - this will let you check the Windows Event Logs for more details on what happened during the backup event.
P.S. Additional info can be found in the following thread describing similar issue.
Thanks for your response.
Going through your checks:
1. "Backup (volume checkpoint)" checkbox is already checked.
2. I have added the registry key as well detailed in the Acronis KB here that you pointed me to and rebooted the machine. Again the three entires are all logged for both servers logs when they are backed up.
3. We run two backup of each virutal machine overnight, one native and one aronis. The native one runs fine without any log entries in relation to the network or warnings/errors.
In this case the issue should be investigated with help from our support team (remember to log under your Acronis account to access all available options) in order to discover the root cause - obviously it's an abnormal behavior.